ci: Add workflow for automated release PRs (shaka-project#3942)

This includes a temporary config file to bootstrap the workflow for
the master branch, whose commit and branch history is too confusing
for the tool to handle with defaults.  After v3.4.0 is released from
the master branch, these configs can be deleted.

Author: joeyparrish

.github/workflows/release.yaml

@@ -0,0 +1,57 @@
+on:
+  push:
+    branches:
+      - master
+      - v[0-9]*
+
+name: Release
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    outputs:
+      release_created: ${{ steps.release.outputs.release_created }}
+      tag_name: ${{ steps.release.outputs.tag_name }}
+    steps:
+      # Create/update release PR
+      - uses: google-github-actions/release-please-action@v3
+        id: release
+        with:
+          # Without this command, the manifest file will be ignored.  At least
+          # for our initial master-branch releases using this workflow, we must
+          # use the manifest and config file.
+          command: manifest
+          config-file: .release-please-config.json
+          manifest-file: .release-please-manifest.json
+          # Make sure the player version gets updated.
+          extra-files: lib/player.js
+          # Make sure we create the PR against the correct branch.
+          default-branch: ${{ github.ref_name }}
+
+  # The jobs below are all conditional on a release having been created by
+  # someone merging the release PR.  They all run in parallel.
+
+  npm:
+    runs-on: ubuntu-latest
+    needs: release
+    if: ${{ needs.release.outputs.release_created }}
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 12
+          registry-url: 'https://registry.npmjs.org'
+      - run: npm ci
+      - run: npm publish
+        env:
+          NODE_AUTH_TOKEN: ${{secrets.NPM_TOKEN}}
+      - run: npm pack
+      - uses: svenstaro/upload-release-action@483c1e56f95e88835747b1c7c60581215016cbf2
+        with:
+          repo_token: ${{ secrets.GITHUB_TOKEN }}
+          tag: ${{ needs.release.outputs.tag_name }}
+          file: shaka-player-*.tgz
+          file_glob: true
+          overwrite: true
+
+  # TODO: Publish to appspot

.npmignore

@@ -2,6 +2,7 @@
 .git
 .gitattributes
 .gitignore
+.release-please*
 *.pyc
 docs/api/
 coverage/

.release-please-config.json

@@ -0,0 +1,9 @@
+{
+  "last-release-sha": "c5faf244b30aa0a99af0e1a1bc7cb4340a1a9f91",
+  "packages": {
+    ".": {
+      "include-component-in-tag": false,
+      "release-as": "3.4.0"
+    }
+  }
+}

.release-please-manifest.json

@@ -0,0 +1,3 @@
+{
+  ".": "3.3.0"
+}

CHANGELOG.md

@@ -1,3 +1,5 @@
+# Changelog
+
 ## 3.3.1 (2022-01-28)
 
 Bugfixes:

lib/player.js

@@ -6536,7 +6536,7 @@ shaka.Player.TYPICAL_BUFFERING_THRESHOLD_ = 0.5;
  * @define {string} A version number taken from git at compile time.
  * @export
  */
-shaka.Player.version = 'v3.4.0-pre-uncompiled';
+shaka.Player.version = 'v3.4.0-pre-uncompiled';  // x-release-please-version
 
 // Initialize the deprecation system using the version string we just set
 // on the player.